<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
div{background:#F00;}
.blank{margin:0;padding:0;border:0;height:10px;line-height:10px;background:transparent;}
.b  { position:relative; *zoom:1; }
.b :after { content:""; display:block; clear:both; }; }
</style>
</head>
<body>
<div>hr.blank</div>
<hr class="blank" />
<div>hr.blank</div>
<div>br.blank</div>
<br class="blank" />
<div>br.blank</div>
<div>div.blank</div>
<div class="blank"></div>
<div>div.blank</div>


</body>
</html>
